If you want an iSonic to replace your old 122 the 110 will do perfectly the job, first your 122 was a real 114 Liters and the 2014 iSonic 110 is a 112 liters but more modern and efficient.
7.0, 7.8 & 8.6 will perform well on it but in your case the 7.0 and 7.8 will make enjoy your sailing.